On the last leg of his presidential election campaign in 2007, Nicolas Sarkozy was greeted with cheers from his supporters when he attacked France's "cynical" and "immoral" Left, the gauche caviar, whom he blamed for a crisis of "morality, authority, work and national identity". Evoking the memory of the student upheavals of 1968, he left his audience in no doubt as to when the rot set in: "In this election, it is a question of whether the heritage of May '68 should be perpetuated or if it should be liquidated once and for all."

It was exhilarating to hear, this side of the Channel. French politics, unlike ours, still includes discussion of the big questions. Tony Blair once touched on a similar theme, when he suggested in a Daily Mail-ish way that maybe, since the sixties, the pendulum had swung too far the wrong way. But it sounded opportunistic to British media ears and, generally, our own senior politicians steer clear of anything so sweeping. Culture wars are out of bounds. Sarkozy's recent remarks on the undesirability of the burka in the wider context of French culture made one realise how timid those who aspire to lead us here have become.

The same goes for our movies. The new French film, Born in 68, which follows the lives of a group of friends and sprawls over four decades of what is now known as "contemporary history", might just make it to TV here or it would be nowhere. In fact, it has been on TV: the BBC's excellent Our Friends in the North covered much the same territory, only with grittier backgrounds and uglier people. Born in 68 started out as a TV project but enough confidence existed for it to be pushed on to the big screen. In the UK, it's hard to imagine such a film making it to the multiplexes: you're Ken Loach or Richard Curtis or you're nothing.

Whether it was worth it depends on your patience and your tolerance for soap opera. The directors, Oliver Ducastel and Jacques Martineau, start with three 20-year-old characters, Catherine (Laetitia Casta), Yves (Yannick Renier) and Hervé (Yann Trégouët), each of them full of utopian passion and yearning for something or other, each one of them improbably beautiful. Inspired by the student turmoil taking place around them, revolted by de Gaulle and everything that has gone before, they take off to the countryside and establish a commune in an abandoned farmhouse. Friends come and go, there's a lot of free love and drippy guitar playing. Catherine remains staunch in her desire to establish an alternative way of living, while the two men eventually make different choices and spend the remaining two hours (at 170 minutes this is a long haul) living with the consequences.

The second half of the movie starts in 1989 and concentrates on the children Catherine and Yves produced in between goat-tending and chanting for rain: Boris, gay and, yes, beautiful, living in the Aids era, and Ludmilla, who marries a well-born (and handsome) Iranian. The Berlin Wall comes down, the internet makes a gradual appearance and the remaining characters watch as Sarkozy denounces them. They wonder what went wrong.

What went wrong, at least as far as the film is concerned, was that move to the country. If the point was to link the characters to the great issues and events of the day, it seems odd to have taken them out of the maelstrom of events and put them in a position where all they can do is react to various news stories as they occasionally flicker across a TV screen. A cheer goes up around the rustic dinner table when François Mitterrand is elected. There are boos when Jacques Chirac eventually follows him. Now ensconced in a smart Paris apartment, Yves has a virtual nervous breakdown as he watches the news that Jean-Marie Le Pen has reached the presidential run-off. The onset of Aids allows Boris to become politically active, but he is a single issue protester and the demonstrations he joins are nothing like as resonant as the évènements which started the whole ball rolling decades earlier.

What we're left with is something altogether more superficial, an everyday story of dissatisfied folk. Babies are born, people age convincingly and others die. Famous songs come and go. Like a good TV series, this all remains perfectly watchable. It would have worked perfectly adequately if there had been no political element at all.

But one assumes from the chronological structure of the movie and its sense of self-importance that there was a desire to make certain bigger points. If this was the case, then it completely fails. There is a frustrating disconnection between the personal drama going on and the narrative of history bubbling away in the background. More importantly perhaps, there seems to be a lack of viewpoint. The older characters retain their knee-jerk sympathies in the face of massive events which should surely make them question them. The country might move from Left to Right, but our friends remain seemingly untouched. Are we to assume that the film-makers admire them for sticking through thick and thin to what passes for their principles? Or are we to see them as self-indulgent, self-regarding, stunted adolescents caught in some permanent rebellion against Mummy and Daddy?

My guess is that the directors would proclaim it a virtue to be as impartial as possible — we should make up our own minds. The casting, however, gives them away. We're much less likely to cheer on nihilistic narcissists if they're fat and buck-toothed (Laetitia Casta, when she's not making films, is also a supermodel). Young, beautiful, revolting: it makes you sigh for the good old days.